Inspection Procedure H-4
INSPECTION PROCEDURE H-4: Rear Wiper and Washer: Rear washer does not operate.
NOTE:
This troubleshooting procedure requires use of scan tool MB991958 and SWS monitor kit MB991813.
For details on how to use the SWS monitor, refer to "How to use SWS monitor How to Use SWS Monitor."
CIRCUIT OPERATION
The rear washer switch sends a signal through the column-ECU (incorporated in the column switch) to the ETACS-ECU. If the column-ECU sends a rear washer switch "ON" signal to the ETACS-ECU, the ETACS-ECU turns on the relay (incorporated in the ETACS-ECU), thus causing the windshield and rear washer motor to be turned on.
TECHNICAL DESCRIPTION (COMMENT)
If the rear washer does not work normally, the windshield and rear washer motor, the column switch (windshield wiper and washer switch), ETACS-ECU or the front-ECU may be defective.
TROUBLESHOOTING HINTS
- The windshield and rear washer motor may be defective
- The column switch (windshield wiper, washer switch) may be defective
- The ETACS-ECU may be defective
- The front-ECU may be defective
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles communication interface (V.C.I.)
- MB991827: M.U.T.-III USB cable
- MB991911: M.U.T.-III Main harness B
- MB991813: SWS monitor kit
- MB991806: SWS monitor cartridge
- MB991812: SWS monitor harness (for column-ECU)
- MB991922: Probe harness
STEP 1. Verify the rear wiper.
Q. Does the rear wiper operate?
YES Go to Step 2.
NO Refer to Inspection Procedure H-1 "Rear wiper does not work at all Inspection Procedure H-1."
STEP 2. Check the input signal by using "FUNCTION DIAG." menu of the SWS monitor.
Set each switch to the following condition before checking input signals from the rear washer switch:
- Ignition switch: ACC
- Rear washer switch: ON
(1)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958. Connect special tool MB991910 before connecting special tool MB991812. Be sure to connect special tool MB991806 after turning on special tool MB991824.
Connect the special tool. Refer to "How to connect SWS monitor How to Connect SWS Monitor."
(2)Operate the scan tool MB991958 according to the procedure below to display "REAR WASHER."
.....Select "System select."
.....Select "SWS."
.....Select "SWS MONITOR."
.....Select "Function Diag."
.....Select "REAR WIPER."
.....Select "REAR WASHER."
(3)Check that normal condition is displayed for the item described in the table below.
Q. Is normal condition displayed?
YES Go to Step 3.
NO Refer to Inspection Procedure M-7 "ETACS-ECU does not receive a signal from the rear washer switch Inspection Procedure M-7."
STEP 3. Check the windshield and rear washer motor connector A-32 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q. Is windshield and rear washer motor connector A-32 in good condition?
YES Go to Step 4.
NO Repair or replace the damaged component(s). Harness Connector Inspection. Verify that the rear washer works normally.
STEP 4. Check the windshield and rear washer motor.
(1)Disconnect windshield and rear washer motor connector A-32.
(2) Fill the washer tank with washer fluid.
(3)When battery voltage is applied between terminals 1 and 2, washer fluid should spray out.
Q. Does the windshield and rear washer motor operate normally?
YES Go to Step 5.
NO Replace the windshield and rear washer motor. Verify that the rear washer works normally.
STEP 5. Check the front-ECU connector A-14X.
(1)
Q. Is the check result normal?
YES Go to Step 6.
NO Repair the connector.
STEP 6. Check the wiring harness between front and rear washer motor connector A-32 (terminal 2) and front-ECU connector A-14X (terminal 31).
- Check the communication lines for open circuit and short circuit.
Q. Is the check result normal?
YES Go to Step 7.
NO Repair the wiring harness.
STEP 7. Check the ETACS-ECU connector C-219.
Q. Is the check result normal?
YES Go to Step 8.
NO Repair the connector.
STEP 8. Check the wiring harness between front and rear washer motor connector A-32 (terminal 1) and ETACS-ECU connector C-219 (terminal 23).
- Check the communication lines for open circuit and short circuit.
NOTE:
Also check intermediate connector C-24 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If junction block intermediate connector C-24 is damaged, repair or replace damaged component(s) as described in Harness Connector Inspection Harness Connector Inspection.
Q. Is the check result normal?
YES Go to Step 9.
NO The wiring harness may be damaged or the connector may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.
Verify that the rear washer works normally.
STEP 9. Replace the ETACS-ECU, and then check its operation.
Replace the ETACS-ECU, and then check that the rear washer works normally.
(1)Replace the ETACS-ECU.
(2)Ignition switch: ON
(3)The rear washer should now work normally.
Q. Is the check result satisfactory?
YES The trouble can be an intermittent malfunction How to Cope With Intermittent Malfunctions).
NO Replace the front-ECU.